Pluvial floods

A pluvial flood, or surface water flood, concerns the floods independent of an overflowing water body and it’s created by heavy rainfall. This kind of flood can happen everywhere, in urban or rural areas and also in areas where there’s no water bodies. The pluvial flooding is caused in two different ways.

The first one when the drainage system is saturated by a rainfall; after the system is overwhelmed the water flows into the streets and the structures (Figure 2, left).

The second one concerns the run-off or flowing water from rain falling on elevated terrain. For example, the hillsides, that are unable to absorb the water (Figure 2, right).

This kind of flood is a slow process in the sense that it doesn’t cause an immediate threat; it gives people time to leave the area affected. In fact, pluvial floods occur gradually and the water level is not very high (very rarely over 1 meter). However, it may cause significant economic damages (Four Common Types of Flood Explained, s. d.).

Representation of a fluvial flood (Four Common Types of Flood Explained, s.d.)